Apparatus and method for liquid purification

ABSTRACT

Apparatus, methods, and systems for separating a fluid mixture are provided which employ gas-handling equipment operable to introduce a gas into the liquid mixture prior to being dispersed within the apparatus, vacuum conditions, and internal condensing. The liquid mixture is dispersed within the separation apparatus as micro-sized droplets. A more volatile portion of the liquid mixture is vaporized when exposed to the vacuum conditions and separates from the non-vaporized liquid portion. The vaporized portion is directed to a condensing structure within the apparatus, which condenses the vaporized portion into a liquid product.

CROSS REFERENCE TO RELATED APPLICATION

This application is a continuation of application Ser. No. 13/970,391,filed Aug. 19, 2013, entitled APPARATUS AND METHOD FOR LIQUIDPURIFICATION.

BACKGROUND OF THE INVENTION

Field of the Invention

The apparatus, methods, and systems described herein are useful forseparating fluid mixtures. In one embodiment, the apparatus, method, andsystem can be used to separate a fluid stream comprising a raw oruntreated water source having a most volatile fraction, a less volatilefraction, and a least volatile fraction, the less volatile fractionbeing predominantly pure water. The separation is accomplished throughthe use of a separation apparatus operating at vacuum conditions andmoderate temperatures.

Description of the Prior Art

Access to sources of potable water is a concern particularly in areasnot served by municipal water-treatment plants. In such areas, stream,lake or even ground water can become contaminated with agricultural andindustrial pollutants such as pesticides, herbicides, fertilizers,fracking fluids and other volatile organic compounds. Fresh water canalso be a scarce resource in locales adjacent saltwater bodies.Contaminants, including brine from seawater, must be separated beforethe water can be rendered suitable for animal or human consumption. Evenif rendering water potable is not a concern, various industrialapplications require water that is free from minerals or corrosivecontaminants that might lead to equipment fouling. Thus, separation ofliquid mixtures, particularly when water is a predominant component ofthe mixture, is an important concern.

Liquid mixture separators and systems often require large, immobilepieces of equipment, such as distillation columns and decanters. Inseparators that vaporize a portion of the liquid mixture, an externalcondenser is required to condense the vapor to recover the desiredliquid product. Providing the necessary cooling for the externalcondenser often requires additional costly energy input. Further, toachieve the desired separation, distillation columns must be designed toinclude many separation trays, raising initial capital costs. Such largeand energy intensive equipment is impractical for use when mobility isrequired or in remote locations, for example, when water purification isneeded in response to a natural disaster.

SUMMARY OF THE INVENTION

In one embodiment of the present invention there is provided anapparatus for separating a mixture of at least two materials havingdifferent volatilities. The apparatus comprises a tubular outer housingdefining a vacuum chamber located within the housing, a fluid-collectiontrough defining a vaporization zone, one or more spray nozzles locatedwithin the vaporization zone, and a condensing structure located withinthe housing and operable to introduce a condensing fluid into the vacuumchamber. A liquid mixture supply conduit feeds the liquid mixture intothe vacuum chamber and disperses the liquid into the vaporization zonethrough the spray nozzles as finely dispersed droplets. At least aportion of the liquid mixture is vaporized upon exposure to the vacuumconditions and exits the vaporization zone through a vapor passage.Optionally, a mesh material may be disposed within the vapor passage toprevent any non-vaporized portion of the mixture from escaping thevaporization zone. Upon exiting the vaporization zone, the vapor portioncontacts the condensing fluid, condensing at least a portion of thevapor product to form a liquid product. Any non-vaporized portion of theliquid mixture introduced into the vaporization zone is collected by thefluid-collection trough and discharged from the housing.

In another embodiment of the present invention there is provided anapparatus for separating a mixture of at least two liquids havingdifferent volatilities. The apparatus comprises a tubular outer housingdefining a vacuum chamber located within the housing, a fluid-collectiontrough defining a vaporization zone and including a hollow structureconstructed to allow one or more temperature control conduits to passthrough, one or more spray nozzles located within the vaporization zone,and a condensing structure located within the housing. A liquid mixturesupply conduit feeds the liquid mixture into the vacuum chamber anddisperses the liquid into the vaporization zone through the spraynozzles as finely dispersed droplets. At least a portion of the liquidmixture is vaporized upon exposure to the vacuum conditions and exitsthe vaporization zone through a vapor passage. Optionally, a meshmaterial may be disposed within the vapor passage to prevent anynon-vaporized portion of the mixture from escaping the vaporizationzone. Temperature control conduits may be disposed within the vaporpassage to maintain a constant contact temperature on the surface of themesh material. Upon exiting the vaporization zone, the vapor portioncontacts the condensing structure, condensing at least a portion of thevapor product to form a liquid product. Any non-vaporized portion of theliquid mixture introduced into the vaporization zone is collected by thefluid-collection trough and discharged from the housing.

In still another embodiment of the present invention there is provided asystem for separating a liquid mixture comprising a most volatilefraction, a less volatile fraction, and a least volatile fraction,wherein the less volatile fraction comprises the predominant componentof the liquid mixture. The system comprises a first upstream separationapparatus and a second downstream separation apparatus, with a first andsecond gas-handling apparatus operable to introduce a gas component intothe liquid mixtures before feeding them into the respective separationapparatuses. The first separation apparatus comprises a tubular outerhousing defining a vacuum chamber, a fluid-collection trough defining avaporization zone and a vapor passage, and one or more spray nozzles forintroducing the liquid mixture in to the vaporization zone as finelydispersed droplets. The first separation apparatus is operable toseparate the most volatile fraction from the liquid mixture. The secondseparation apparatus comprises a tubular outer housing defining a vacuumchamber, a fluid-collection trough defining a vaporization zone and avapor passage, one or more spray nozzles for introducing the liquidmixture into the vaporization zone as finely dispersed droplets, and acondensing structure disposed to contact and condense at least a portionof the vaporized mixture to form a liquid product. The liquid productmay comprise a substantially pure amount of the less volatile fraction.

In yet another embodiment of the present invention there is provided amethod for separating a mixture of at least two materials havingdifferent volatilities. The method comprises introducing a gas into afeed stream of the liquid mixture, so as to cause at least a portion ofthe gas to become dissolved within the mixture, and subsequentlydirecting the gas-containing mixture into a separation apparatusoperating under vacuum conditions. Within the separation apparatus, themixture is transported along at least a portion of the length of avaporization zone defined by a fluid-collection trough disposed withinthe housing. The mixture is dispersed within the vaporization zone as aplurality of finely dispersed droplets causing the more volatilecomponents of the mixture to vaporize. The vaporized portion iscondensed within the housing and collected as liquid product. Thenon-vaporized portion is delivered to a waste stream within the troughand removed from the housing.

BRIEF DESCRIPTION OF THE DRAWING

FIG. 1 is a perspective view of a liquid separation apparatus accordingto one embodiment of the present invention;

FIG. 2 is a perspective view of the apparatus in FIG. 1 with sectionsremoved to expose the inner components of the apparatus;

FIG. 3 is a perspective view of the apparatus in FIG. 1 from a differentangle and with different sections removed than FIG. 2;

FIG. 4 is a broken cross-sectional view of the apparatus in FIG. 1exposing the components along the longitudinal central axis of theapparatus;

FIG. 5 is a view of the apparatus of FIG. 4 taken along line 5-5;

FIG. 6 is an exploded view of the apparatus in FIG. 1;

FIG. 7 is a perspective view of a liquid separation apparatus accordingto an alternate embodiment of the present invention;

FIG. 8 is a perspective view of the apparatus in FIG. 7 with sectionsremoved to expose the inner components of the apparatus;

FIG. 9 is a perspective view of the apparatus in FIG. 7 from a differentangle and with different sections removed than FIG. 8;

FIG. 10 is a partial broken cross-sectional view of the apparatus inFIG. 7 exposing the components along the longitudinal central axis ofthe apparatus;

FIG. 11 is an exploded view of the apparatus in FIG. 7;

FIG. 12 is a perspective view of a liquid separation apparatus accordingto another embodiment of the present invention with sections removed toexpose the inner components of the apparatus;

FIG. 13 is an end elevation view of the apparatus in FIG. 12, inparticular illustrating an end cap through which a number of linescommunicating with the interior of the apparatus are located;

FIG. 14 is a broken, cross-sectional view of the apparatus of FIG. 13taken along line 14-14 to expose the inner components of the apparatus;

FIG. 15 is a view of the apparatus of FIG. 14 taken along line 15-15 toexpose the inner components of the apparatus; and

FIG. 16 is a schematic diagram of a fluid separation system made inaccordance with an embodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Apparatus, methods, and systems according to the present invention aredirected toward separating a liquid product from a liquid mixture. Theapparatus is particularly useful in separating a more volatile fractionfrom a less volatile fraction in a liquid mixture to recover asubstantially pure liquid product that is essentially free of thecomponents less volatile fraction. In certain embodiments, the apparatusmay be constructed to be portable so as to allow separation of any rawliquid feed in a variety of locations. For example, the apparatus may beplaced on or within a trailer that can be transported between locationsvia a semi-tractor. In another embodiment, the systems are particularlyuseful in separating a more volatile fraction, a less volatile fraction,and a least volatile fraction in a liquid mixture to recover a liquidproduct comprising substantially pure less volatile component.

Turning to the drawings, and FIG. 1 in particular, a separationapparatus 10 according to one embodiment of the present invention isshown. Separation apparatus 10 comprises a tubular outer housing 20. Endcaps 32 and 33 are secured to outer housing 20 by one or more drawlatches 31; however, any type of fastener known to those of skill in theart may be used to secure caps 32, 33 to housing 20. A liquid mixturefeed line 40 enters outer housing 20 through cap 32 and exits housing 20through cap 32 by way of outlet 44. A liquid product outlet 48 andliquid discharge outlet 46 are secured to, and extend outwardly from cap32. In certain embodiments of the present invention, condenser fluidinlet 50 enters housing 20 through cap 32. Cap 32 also includes a vacuumport 35, which allows a mechanical vacuum device (not shown) to beattached and maintain substantially vacuum conditions within the spaceddefined by outer housing 20. In certain embodiments of the presentinvention, the tubular housing 20 has a substantially horizontallongitudinal central axis, but it is within the scope of the presentinvention for housing 20 to be slightly inclined to assist with gravitydraining of various product streams. In certain embodiments, thisincline is less than 10°, less than 5°, or less than 2° relative to thehorizontal.

As can be seen in FIG. 3, the boundaries of outer housing 20 define avacuum chamber 80 within the housing 20. The components of separator 20residing within vacuum chamber 80 are further illustrated in FIG. 2.Feed line 40 is directed along the length of housing 20 into avaporization zone 60 through one or more liquid mixture supply conduits43. Supply conduit 43 is equipped with one or more nozzles 63 forintroducing the liquid mixture into a vaporization zone 60. Supplyconduit 43 continues substantially along the length of housing 20 towardend cap 33. Conduit 43 then makes a U-turn and directs the liquidmixture carried thereby back along the length of housing 20, exitinghousing 20 through feed outlet 44. In certain embodiments, nozzles 63are spray nozzles operable to introduce the liquid mixture intovaporization zone 60 as a finely dispersed mist comprising micro-sizeddroplets. Any amount of the liquid mixture that is not introduced intovaporization zone 60 via nozzles 63 is directed by conduit 43 out ofhousing 20 through liquid mixture outlet 44. This portion of the liquidmixture may be returned to its source (e.g., a holding tank or naturalbody of water), or directed toward another apparatus 10 connected inseries.

Vacuum chamber 80 further comprises a fluid-collection trough 70. Incertain embodiments of the present invention, the longitudinalhorizontal axis of fluid collection trough 70 runs substantiallyparallel to the longitudinal horizontal axis of outer housing 20, oreven may be coaxial therewith. One or more trough supports 72 areattached to the outer wall of the fluid-collection trough 70 and aredisposed to maintain a certain spatial relationship between the trough70 and outer housing 20. In certain other embodiments, a mesh material65 is disposed above trough 70 and supply conduit 63 in a vapor passage64, more clearly shown in FIG. 5. Mesh material 65 preferably comprisesa screen made from a metal or synthetic resin material. In preferredembodiments, mesh material 65 is non-corrosive so that contact with thefluids being handled by apparatus 10 (namely, aqueous fluids) does notcorrode or degrade the material. Mesh material 65 is secured into placeabove the trough 70 by mesh attachments 79. FIG. 3 shows another view ofthe contents of vacuum chamber 80, including internal draw latches 71for securing fluid collection trough 70 to front end cap 32. Again, anytype of fastening device may be substituted for latches 71.

Apparatus 10 further comprises a condenser fluid supply conduit 54extending into vacuum chamber 80 and directed along the length ofhousing 20 in disposition above fluid collection trough 70. In certainembodiments, condenser fluid supply conduit 54 directs condensing fluidsupplied via inlet 50 into vacuum chamber 80 through end cap 32 alongthe length of housing 20 toward end cap 33. In certain otherembodiments, such as the embodiment shown in FIGS. 7-11, condenser fluidfeed 50 enters housing 20 through condenser inlet 52 disposed in thewall of housing 20. Regardless of the entry point, condenser fluidsupply conduit 54 directs condenser fluid feed 50 along the length ofhousing 20 toward either the front end cap 32, back end cap 33, or both.Conduit 54 may comprise one or more condenser fluid outlets 53 operableto introduce a condensing fluid into the vacuum chamber 80. In theembodiment of FIGS. 7-11, liquid product outlet 48 is disposed withinhousing 20, rather than end cap 32. FIG. 6 is an exploded view ofapparatus 10 illustrating assembly of the various components thereof. Ascan be seen, apparatus 10 further comprises a gasket 36 configured toseal between end cap 32 and trough 70, a trough end cap 38 configured toseal the end of trough 70 adjacent end cap 33, and an O-ring 39 operableto provide a seal between housing 20 and end cap 33.

In the above-described embodiments of the present invention illustratedby FIGS. 1-11, a liquid mixture is fed to separation apparatus 10 byliquid mixture feed line 40. The liquid mixture may have previouslyundergone some kind of pre-treatment operation, such as will bedescribed in greater detail below with reference to FIG. 16. In certainembodiments, this pre-treatment may include the filtering or removal ofundissolved solids. In certain embodiments, the liquid mixture may alsoinclude dissolved gasses that are deliberately introduced into theliquid mixture in order to assist with product separation. In otherembodiments, the liquid mixture may contain dissolved solids, such asmetal ions (e.g., from brine) and surfactants. In one particularembodiment, the liquid mixture may be a fluid used in downhole frackingoperations. While generally fracking fluid comprises predominantly waterand sand, the fracking fluid may also contain any number of additivessuch as ethylene glycol, borate salts, sodium and potassium carbonate,guar gum, and isopropanol that must be removed before the fluid can bedischarged into the environment. In other embodiments, the liquidmixture may comprise high-salinity seawater, or fresh water that may becontaminated with various microbes and disease-causing pathogens.

The liquid mixture is supplied to apparatus 10 by feed line 40. Themixture is then carried by liquid mixture supply conduit 43 along atleast a portion of the length of housing 20 within the vaporization zone60 defined at least in part by fluid-collection trough 70. The liquidmixture carried by conduit 43 is dispersed into vaporization zone 60 asa plurality of fine, micro-sized droplets via nozzles 63. Nozzles 63 maybe configured to disperse the liquid mixture as droplets having averagedroplet sizes of between about 20 to about 60 microns, between about 30to about 50 microns, or about 40 microns. It should be appreciated thatthe term “nozzle” may include any structure or orifice operable tointroduce the liquid mixture into the vaporization zone 60. Uponspraying into vaporization zone 60, the dissolved gasses within thedroplets are rapidly liberated thereby causing the micro-sized dropletsto burst into a plurality of even smaller droplets (i.e.,submicron-sized) having a greatly reduced surface tension, which resultsin a reduced liquid vapor pressure. This physical characteristic isdescribed in more detail in U.S. Patent Application Publication No.2010/0264013, incorporated by reference herein in its entirety.

Within vaporization zone 60, the droplets are exposed to vacuumconditions, which cause at least a portion of the more volatile fractionto vaporize and separate from the liquid mixture. The vaporized portionof the mixture passes through vapor passage 64 (see, e.g., FIG. 5)outwardly toward the inner wall 22 of outer housing 20. After exitingvaporization zone 60 through vapor passage 64, the vaporized portion maybe either discharged as a waste stream through vacuum port 35(especially if apparatus 10 is to be used to separate VOCs from thefluid mixture as described further below) or other discharge outlet, orthe vapor may be condensed and recovered as a condensed liquid product.Any liquid mixture remaining in feed line 40 and not introduced intovaporization zone 60 continues through conduit 43 and is directed out ofseparation apparatus 10 through feed outlet 44.

The non-vaporized portion of the liquid mixture introduced intovaporization zone 60 via nozzles 63 does not pass through vapor passage64. In certain embodiments, mesh material 65 operates to catch andcoalesce liquid droplets comprising the least volatile fraction of theliquid mixture that may have otherwise passed through vapor passage 64.Mesh material 65 may be substantially M-shaped in cross section, asshown in FIG. 5, or any other shape that effectively prevents the liquidportion from passing through vapor passage 64 while allowing the vaporportion through. In certain embodiments, mesh material 65 can isolateeach individual nozzle 63 such that the spray pattern from one nozzledoes not overlap or impinge upon the spray pattern of another, adjacentnozzle. The non-vaporized liquid portion comprising the least volatilefraction is collected in a channel 74 of fluid-collection trough 70 anddirected out of the apparatus 10 through liquid discharge outlet 46 forfurther treatment or disposal.

In certain embodiments of the present invention, condenser fluid conduit54 directs a condensing fluid from condenser feed 50 along at least aportion of the length of housing 20. The condensing fluid, which ispreferably a recycle of the product fluid separated from the liquidmixture, is introduced into vacuum chamber 80 through one or morecondenser fluid outlets 53 along the inner wall of outer housing 20.Condenser fluid outlets 53 are disposed such that the vapor portionleaving vaporization zone 60 through vapor passage 64 comes into contactwith the condensing fluid. When the vapor portion contacts thecondensing fluid, at least a portion of the vapor is condensed and mixeswith the condensing fluid to form a condensed liquid product. In certainembodiments, the condensing fluid and condensed liquid product flowsradially in laminar flow along the inner wall 22 toward a condensedliquid collection zone 82 located in the space between fluid-collectiontrough 70 and outer housing 20. The condensed liquid mixture flowinginto the fluid collection zone 82 is then directed out of the vacuumchamber 80 of separation apparatus 10 through liquid product outlet 48.

FIGS. 12-15 illustrate another embodiment of the present invention thatshares some similarities with the embodiments of FIGS. 1-11 describedabove. Turning first to FIGS. 12 and 13, a fluid separation apparatus110 is shown comprising end caps 132 and 133 secured to a housing 120 byone or more draw latches 131. The liquid mixture feed line 140 entersouter housing 120 through cap 132 and exits out of housing 120 throughcap 132 by way of outlet 144. A liquid product outlet 148 and a liquiddischarge outlet 146 also extend outwardly from cap 132. In certainembodiments of the present invention, a condenser fluid feed entershousing 120 through condenser inlet 150 and exits housing 120 throughcondenser outlet 156. A temperature control fluid, whose function isexplained in greater detail below, enters housing 120 through inlet 166and exits through outlet 169. A feed line for supplying a temperaturecontrol fluid to a jacketed trough 170 enters housing 120 through jacketinlet 176 and exits housing 120 through jacket outlet 179. A vacuum port(not shown) may be included in cap 132, just as with the embodimentsdescribed previously, or in the wall of housing 120, which allows amechanical vacuum device (not shown) to be attached and maintainsubstantially vacuum conditions within the outer housing 120.

Outer housing 120 and end caps 132, 133 cooperate to define a vacuumchamber 180 within housing 120. FIGS. 14 and 15 best illustrate thevarious components of separation apparatus 110 located within vacuumchamber 180. The liquid mixture supplied by feed line 140 is directedinto a vaporization zone 160 via supply conduit 143. Supply conduit 143is equipped with one or more nozzles 163 for dispersing the liquidmixture within vaporization zone 160. Liquid mixture supply conduit 143continues substantially along the length of housing 120 toward end cap133. Before the conduit 143 reaches end cap 133, it makes a U-shapedturn (i.e., 180°) and is directed back along the length of housing 120toward end cap 132. Before reaching end cap 132, conduit 143 makesanother U-shaped turn and is directed back along the length of housing120 toward back end cap 133. This back-and-forth turning of conduit 143creates a plurality of rows of nozzles 163 operable to disperse theliquid mixture as a fine mist having micro-sized droplets intovaporization zone 160. After a number of passes, any amount of theliquid mixture that is not introduced into vaporization zone 160 iseventually directed by conduit 143 out of housing 120 through liquidmixture outlet 144.

Vacuum chamber 180 further comprises a jacketed fluid collection trough170 comprising a channel 174 and an at least partially hollow wallstructure 175. A temperature control fluid enters vacuum chamber 180 viainlet 176 and is directed into the hollow wall structure 175 by jacketconduit 177. In certain embodiments, hollow wall structure comprises aplurality of longitudinally extending chambers 181 through which atemperature control fluid is supplied or removed via an orifice 183. Thetemperature control fluid may be any fluid known to those of skill inthe art, such as water or a portion of the purified product of apparatus110. In the embodiment illustrated, the temperature control fluid isrouted through each chamber 181 in a serpentine-like manner; however, itis within the scope of the present invention for each chamber 181 to beindependently supplied with temperature control fluid via a distributionheader. After a number of passes, the temperature control fluid isdirected out of housing 120 through outlet 179 in end cap 132. Thetemperature control fluid ensures a constant and uniform temperaturewithin vaporization zone 160 so as to minimize the cooling effect thatthe evaporation of liquid from the droplets dispersed by nozzles 163 hason overall vaporization efficiency. Fluid-collection trough 170comprises one or more trough supports 172 attached to the outer wall ofthe fluid-collection trough 170 and disposed to maintain a the spatialrelationship between the trough 170 and outer housing 120.

Vacuum chamber 180 further comprises vapor passage 164 through whichvapor generated in vaporization 160 passes en route to condensingstructure 149. A temperature control fluid, of the same or differenttype than the temperature control fluid being passed through jacketedtrough 170, is directed into housing 120 via line 166. A vapor passageconduit 167 conducts the temperature control fluid along the length ofhousing 120 within vapor passage 164 toward end cap 133 in aserpentine-like manner). After a number of passes, conduit 167 directstemperature control fluid out of housing 120 through outlet 169. Conduit167 and the temperature control fluid circulated therethrough serve tocontrol the temperature within vapor passage 164. This structure ensuresthat the product desired for recovery remains in the vapor phase duringits traverse of passage 164 and also provides for condensation of anyundesired material inadvertently vaporized and sought to be collected inchannel 174. A mesh material 165 is disposed above trough 170 and supplyconduit 63 in vapor passage 164, best illustrated in FIG. 15. The meshmaterial 165 may be wound around conduit 167 not only to prevent liquiddroplets from escaping through vapor passage 164, but also to providefurther contact surface for condensation of undesired materials. Incertain embodiments, the temperature control fluid flowing throughconduit 167 is of the same or nearly the same temperature as the fluidflowing through jacketed trough 170. However, this need not always bethe case.

Condensing structure 149 further comprises a condenser fluid supplyconduit 154 directed along the length of housing 120 and disposed abovefluid collection trough 170. In certain embodiments, condenser fluidsupply conduit 154 may be covered with bonnet structures 157, 158, and159, which are preferably fabricated of a non-corrosive sheet metalmaterial. Condenser fluid supply conduit 154 is fed with condensingfluid via inlet 150. Conduit 154 then generally traverses within vacuumchamber 180 in a serpentine manner, immediately above trough 170 for aplurality of passes. The condensing fluid flowing through conduit 154 isgenerally of a sufficient temperature to condense the vapor componentthat has passed through passage 164. Bonnet structures 157-159 serve todirect the flow of vapor within vacuum chamber 180 outside ofvaporization zone 160. At least a portion of the vapor from passage 164is directed in between bonnets 157, 159 and then deflected by bonnet 158over conduit 154. The fluid condensed by bonnet 158 and conduit 154 isdirected over the outboard surfaces of bonnets 157, 159 toward fluidcollection zone 182. Another portion of the vapor from passage 164contacts the inboard surfaces of bonnets 157, 159 whereby a portion ofthe vapor is condensed as liquid product as a result of therefrigeration provided by the condensing fluid within conduit 154. Thecondensed fluid tends to cling to the inboard surfaces of bonnets 157,159 and too is directed toward fluid collection zone 182. The condensingfluid exits condensing structure 149 via outlet 156.

The non-vaporized portion of the liquid mixture introduced intovaporization zone 160 is collected in a channel 174 of fluid collectiontrough 170 and directed out of the apparatus 110 through liquiddischarge outlet 146. The recovered liquid product is discharged fromapparatus 110 through outlet 148.

Turning to FIG. 16, a system for recovering a liquid product from aliquid mixture made in accordance with one embodiment of the presentinvention is shown. A stream 201 of a raw liquid mixture is provideddelivered from a liquid source, such as a well, stream, pond, or lake,via a pump assembly 200. Assembly 200 may include a trash filtrationsystem to remove large solid particulates drawn into the system by thepump. As the exact composition of the raw liquid mixture is likely to beunknown absent analytical testing, in certain embodiments, liquidmixture feed stream 201 is assumed to comprise a most volatile fraction,a less volatile fraction, and a least volatile fraction. The mostvolatile fraction may comprise volatile organic compounds or othervolatile components. A check valve 202 is provided to ensureunidirectional flow of stream 201 and prevent backflow of the raw liquidmixture into pump assembly 200. Feed stream 201 is then directed througha primary filtration system 203 where additional solid particulatesentrained within the raw liquid mixture are removed. The stream is thenwarmed in a heat exchanger 205 and delivered to a warmed feed holdingtank 210.

Warmed liquid mixture stream 212 is pumped out of warmed feed holdingtank 210 by pump 211 and directed through an exhaust gas heat exchanger215. Heat exchanger 215 is supplied with heat by the exhaust gas from agenerator 300. Generator 300 may be diesel fueled or any other type ofheat-generating system. From heat exchanger 215, stream 212 is fed intoprimary heated liquid holding tank 220. In certain embodiments, such asthose where the heated liquid comprises water at the majority component,the temperature of the heated liquid within holding tank 220 may bebetween about 90° F. to about 130°, or between about 100° F. to about120 F. Heated liquid mixture stream 221 is pumped out of holding tank220 by pump 226 and directed through a gas-handling apparatus 225operable to dissolve a gas component into heated liquid mixture stream221 to form gas-containing mixture stream 227. In certain embodiments,gas-handling apparatus 225 comprises a gas diffuser operable to dissolvea gas, such as air, carbon dioxide, nitrogen, oxygen, or any combinationthereof, into the liquid mixture. Any non-dissolved gasses introducedinto stream 221 can be removed via a gas release valve located at thetop of the diffuser. The dissolved gas-containing mixture stream 227should be at a temperature and composition such that the most volatilefraction will vaporize when exposed to vacuum pressure conditions.

Dissolved gas-containing mixture stream 227 is fed into a separationvessel 230. In certain embodiments, separation vessel 230 is constructedsimilarly to a separation apparatus as shown in FIGS. 1-15. However, thefunction of separation vessel 230 is to separate the most volatilefraction from the liquid mixture thereby leaving the desired liquidproduct as the next most volatile component remaining. As recovery ofthe most volatile component is not a primary objective, separationvessel 230 need not be provided with condenser structure. But, in allother respects, separation vessel 230 may be constructed as describedabove. As noted above, the separation vessels described hereincomprising a tubular outer housing defining a vacuum chamber, afluid-collection trough, and a supply conduit comprising one or morespray nozzles. In certain embodiments, separation vessel 230 is operableto separate the most volatile fraction of dissolved gas-containingmixture stream 227. The most volatile fraction is vaporized withinvessel 230 and discharged through a vacuum port (not shown) operablyconnected with a vacuum pump. Any portion of dissolved gas-containingmixture stream 227 not introduced into the vacuum chamber of vessel 230is directed by recycle stream 228 back into warmed feed holding tank210. A check valve 229 can be employed to prevent backflow intoseparation vessel 230.

The non-vaporized portion of stream 227 is collected within vessel 230and subsequently removed therefrom as bottoms stream 231. Primarybottoms stream 231 comprises the less volatile fraction and leastvolatile fraction, with the most volatile fraction having beensubstantially removed by vessel 230. Bottoms stream 231 is fed to oneholding tank assembly 232, comprising one or more holding tanks. Theliquid mixture from holding tank assembly 232 is directed via pump 233as a stream 236 through heat exchanger 235 and gas exhaust heatexchanger 215 where it is warmed. Heat for heat exchanger 235 may besupplied by a heat pump 270. The heated stream 236 is then fed intoexhaust gas heat exchanger 215 before going to a heated liquid holdingtank 240. From holding tank 240, stream 242 is pumped again through heatexchanger 215 and into another heated liquid holding tank 250 by pump241. In certain embodiments, such as where the heated liquid compriseswater as a majority component, the heated liquid within tank 250 has atemperature of between about 160° F. to about 200° F., or between about170° F. to about 190° F., or about 180° F. The heated liquid mixturefrom tank 250 is directed as stream 251 through gas handling apparatus255 by pump 256. Gas handling apparatus 255 is operable to dissolve agas component (e.g., air, carbon dioxide, nitrogen, oxygen or the like)into heated liquid mixture stream 251 to form a dissolved gas-containingmixture stream 257. Like gas-handling apparatus 225, in certainembodiments, gas-handling apparatus 255 may be a diffuser operable tointroduce and dissolve a gas into the liquid mixture. Dissolvedgas-containing mixture stream 257 should now be at a temperature suchthat the less volatile fraction of the liquid mixture will vaporize whenexposed to vacuum pressure conditions, while the least volatile fractionremains liquid.

Dissolved gas-containing liquid mixture stream 257 is fed into anotherseparation vessel 260. In certain embodiments, separation vessel 260 isconfigured as any of the separation vessels described herein comprisinga tubular outer housing defining a vacuum chamber, a fluid-collectiontrough, and a supply conduit comprising one or more spray nozzles.Unlike separation vessel 230, because the vaporized component is to berecovered, separation vessel 260 further comprises condensing structureoperable to condense at least a portion of the vapor produced withinvessel 260. In certain embodiments, separation vessel 260 is operable toseparate the less volatile fraction from the least volatile fraction ofdissolved gas-containing mixture stream 257. The less volatile fractionis vaporized and then condensed within vessel 260 to form a liquidproduct that is withdrawn from vessel 260 as product stream 273. Productstream 273 is substantially a pure liquid comprising the less volatilecomponent, which in certain embodiments means that the liquid is greaterthan 99.5% pure. The non-vaporized least volatile fraction, which maycontain dissolved solids, exits vessel 260 as liquid discharge stream263. Liquid discharge stream 263 is directed into one or more dischargeholding tank assembly 265 and eventually out of the system by pump 266.Any portion of dissolved gas-containing mixture stream 257 notintroduced into the vacuum chamber of vessel 260 is directed back intoheated liquid holding tank 240 via stream 261. Again, a check valve 262may be employed to ensure unidirectional flow. Liquid product stream 273is directed into a holding tank assembly 275 and eventually pumped intoproduct holding tank 280 via stream 274 by pump 276. Liquid product ispumped out of holding tank 280 by pump 281 and exits the system. Incertain embodiments of the present invention, the liquid productcomprises water that is between 99.5% and 100% pure.

Optionally, one or more flow control valves may be installed within thesystem to alter the flow path of at least a portion of certain streams.Valve 290 may be installed to direct a portion of liquid product stream274 into condenser recycle stream 277. Recycle stream 277 is cooled byheat exchanger 205 and heat pump 270 to form cooled condenser stream272. Condenser stream 272 is pumped by pump 271 into separation vessel260 to supply at least a portion of the condensing fluid (andpreferably, substantially all of the condensing fluid) operable tocondense the vapor product within separator 260. Valve 297 may beinstalled and operated to permit at least a portion of cooled condenserstream 272 to bypass separator 260 and feed into liquid product stream274 for startup and testing.

Other flow control valves may be installed for temperature control.Valve 291 may be installed to permit stream 212 to bypass heat exchanger215 in situations where no further heating is necessary. In contrast,valve 292 may be installed to permit stream 212 to recycle back intowarmed feed holding tank 210 when more heating is necessary. Similarly,valve 293 may be installed to direct at least a portion of stream 227into holding tank 210 when further heating is necessary to effectvaporization of the most volatile fraction in separation vessel 230.Valves 294, 295, and 296 operate in the same manner as valves 291, 292,and 293, respectively except they control the temperature of the streamsleading to separation vessel 260 and are used primarily in startupoperations.

It is recognized that various pieces of equipment may be redundantlyinstalled to allow for servicing of the equipment while keeping theoverall system operational. For example, multiple pumps could beinstalled in parallel. The plurality of pumps may all be utilized duringstart up of the system, and once a steady state is achieved, one or morepumps could be switched off to reduce operating costs and allow forequipment servicing. Further, additional heat pumps may be utilized tosupply the necessary heating and refrigeration. Electric heaters mayalso be used in place of or to supplement the energy from heat pump 270.

Having thus described the invention, what is claimed as new and desiredto be secured by Letters Patent is:
 1. A method for recovering a liquidproduct from a liquid mixture, said method comprising: introducing a gasinto a stream of said liquid mixture so as to cause at least a portionof said gas to become dissolved within the liquid mixture therebyforming a gas-containing liquid mixture; directing the gas-containingliquid mixture stream into a separation apparatus operating under vacuumconditions, said separation apparatus comprising an outer housing, afluid-collection trough located within said housing and defining atleast in part a vaporization zone and a channel into which liquid may becollected, and a condensing structure located within said housing;transporting the gas-containing liquid mixture along at least a portionof the length of said vaporization zone through one or more liquidmixture supply conduits; dispersing said gas-containing liquid mixturewithin the vaporization zone as a plurality of droplets, causing atleast a portion of said droplets to vaporize thereby forming a vaporproduct, contacting the vapor product with said condensing structure tocondense at least a portion of said vapor product thereby forming theliquid product; recovering any portion of the plurality of droplets notvaporized in said trough; and recovering the liquid product from saidseparation apparatus.
 2. The method according to claim 1, wherein saidmethod further comprises delivering a laminar flow of condensing fluidto an inner wall surface of said housing, the flow of condensing fluidcausing at least a portion of the vapor product to condense.
 3. Themethod according to claim 2, said condensing fluid comprising a portionof said liquid product.
 4. The method according to claim 1, saidcondensing structure including one or more coolant tubes through whichis flowed a coolant having a temperature sufficient to condense at leasta portion of the vapor product.
 5. The method according to claim 1, saidcondensing structure including one or more liquid product collectorsoperable to collect condensed liquid product and/or direct the liquidproduct toward a liquid product outlet.
 6. The method according to claim1, wherein said method further comprises maintaining said vaporizationzone at substantially constant temperature by flowing a warming fluidthrough an at least partially hollow wall structure located within saidtrough.
 7. The method according to claim 1, wherein said method furthercomprises preventing at least a portion of said droplets from escapingsaid vaporization zone through a vapor passage by at least partiallydisposing mesh material within said vapor passage.
 8. The methodaccording to claim 7, wherein said method further comprises flowing atemperature control fluid through one or more temperature controlconduits located within said vapor passage and adjacent to said meshmaterial so as to control the temperature within said vapor passage. 9.The method according to claim 1, wherein said method further comprisesremoving at least a portion of volatile organic compounds from saidliquid mixture prior to introducing said gas into said liquid mixturestream.
 10. A method for recovering a liquid product from a mixture,said method comprising: introducing a gas into said mixture so as tocause at least a portion of said gas to become dissolved in said mixturethereby forming a gas-containing mixture; directing said gas-containingmixture into a separator operating under a vacuum, said separatorcomprising an outer housing, a fluid-collection trough located withinsaid housing and defining at least in part a vaporization zone and achannel into which liquid may be collected, and a condenser locatedwithin said outer housing; transporting said gas-containing mixturealong at least a portion of the length of said vaporization zone throughone or more mixture supply conduits; dispersing said gas-containingmixture within said vaporization zone as a plurality of droplets,causing at least a portion of said plurality of droplets to vaporizethereby forming a vapor, contacting said vapor with said condenser tocondense at least a portion of said vapor thereby forming said liquidproduct; recovering a portion of said plurality of droplets notvaporized in said trough; and recovering said liquid product from saidseparator.
 11. The method according to claim 10, wherein said methodfurther comprises delivering a laminar flow of condensing fluid to aninner wall surface of said housing, said flow of condensing fluidcausing at least a portion of said vapor to condense.
 12. The methodaccording to claim 11, said condensing fluid comprising a portion ofsaid liquid product.
 13. The method according to claim 10, saidcondenser including one or more coolant tubes through which is flowed acoolant having a temperature sufficient to condense at least a portionof said vapor.
 14. The method according to claim 10, said condenserincluding one or more liquid product collectors operable to collect saidliquid product and direct said liquid product toward a liquid productoutlet.
 15. The method according to claim 10, wherein said methodfurther comprises maintaining said vaporization zone at substantiallyconstant temperature by flowing a warming fluid through an at leastpartially hollow wall structure located within said trough.
 16. Themethod according to claim 10, wherein said method further comprisespreventing at least a portion of said plurality of droplets fromescaping said vaporization zone through a vapor passage by at leastpartially disposing mesh material within said vapor passage.
 17. Themethod according to claim 16, wherein said method further comprisesflowing a temperature control fluid through one or more temperaturecontrol conduits located within said vapor passage and adjacent to saidmesh material so as to control the temperature within said vaporpassage.
 18. The method according to claim 10, wherein said methodfurther comprises removing at least a portion of volatile organiccompounds from said mixture prior to introducing said gas into saidmixture.